1 /* 2 * Copyright (C) 2014 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #include <stdio.h> 18 #include <stdlib.h> 19 20 #include <fstream> 21 #include <iostream> 22 #include <string> 23 #include <vector> 24 #include <set> 25 #include <map> 26 27 #include "art_method-inl.h" 28 #include "base/unix_file/fd_file.h" 29 #include "base/stringprintf.h" 30 #include "gc/space/image_space.h" 31 #include "gc/heap.h" 32 #include "mirror/class-inl.h" 33 #include "mirror/object-inl.h" 34 #include "image.h" 35 #include "scoped_thread_state_change.h" 36 #include "os.h" 37 #include "gc_map.h" 38 39 #include "cmdline.h" 40 #include "backtrace/BacktraceMap.h" 41 42 #include <sys/stat.h> 43 #include <sys/types.h> 44 #include <signal.h> 45 46 namespace art { 47 48 class ImgDiagDumper { 49 public: 50 explicit ImgDiagDumper(std::ostream* os, 51 const ImageHeader& image_header, 52 const char* image_location, 53 pid_t image_diff_pid) 54 : os_(os), 55 image_header_(image_header), 56 image_location_(image_location), 57 image_diff_pid_(image_diff_pid) {} 58 59 bool Dump() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 60 std::ostream& os = *os_; 61 os << "MAGIC: " << image_header_.GetMagic() << "\n\n"; 62 63 os << "IMAGE BEGIN: " << reinterpret_cast<void*>(image_header_.GetImageBegin()) << "\n\n"; 64 65 bool ret = true; 66 if (image_diff_pid_ >= 0) { 67 os << "IMAGE DIFF PID (" << image_diff_pid_ << "): "; 68 ret = DumpImageDiff(image_diff_pid_); 69 os << "\n\n"; 70 } else { 71 os << "IMAGE DIFF PID: disabled\n\n"; 72 } 73 74 os << std::flush; 75 76 return ret; 77 } 78 79 private: 80 static bool EndsWith(const std::string& str, const std::string& suffix) { 81 return str.size() >= suffix.size() && 82 str.compare(str.size() - suffix.size(), suffix.size(), suffix) == 0; 83 } 84 85 // Return suffix of the file path after the last /. (e.g. /foo/bar -> bar, bar -> bar) 86 static std::string BaseName(const std::string& str) { 87 size_t idx = str.rfind("/"); 88 if (idx == std::string::npos) { 89 return str; 90 } 91 92 return str.substr(idx + 1); 93 } 94 95 bool DumpImageDiff(pid_t image_diff_pid) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 96 std::ostream& os = *os_; 97 98 { 99 struct stat sts; 100 std::string proc_pid_str = 101 StringPrintf("/proc/%ld", static_cast<long>(image_diff_pid)); // NOLINT [runtime/int] 102 if (stat(proc_pid_str.c_str(), &sts) == -1) { 103 os << "Process does not exist"; 104 return false; 105 } 106 } 107 108 // Open /proc/$pid/maps to view memory maps 109 auto proc_maps = std::unique_ptr<BacktraceMap>(BacktraceMap::Create(image_diff_pid)); 110 if (proc_maps == nullptr) { 111 os << "Could not read backtrace maps"; 112 return false; 113 } 114 115 bool found_boot_map = false; 116 backtrace_map_t boot_map = backtrace_map_t(); 117 // Find the memory map only for boot.art 118 for (const backtrace_map_t& map : *proc_maps) { 119 if (EndsWith(map.name, GetImageLocationBaseName())) { 120 if ((map.flags & PROT_WRITE) != 0) { 121 boot_map = map; 122 found_boot_map = true; 123 break; 124 } 125 // In actuality there's more than 1 map, but the second one is read-only. 126 // The one we care about is the write-able map. 127 // The readonly maps are guaranteed to be identical, so its not interesting to compare 128 // them. 129 } 130 } 131 132 if (!found_boot_map) { 133 os << "Could not find map for " << GetImageLocationBaseName(); 134 return false; 135 } 136 137 // Future idea: diff against zygote so we can ignore the shared dirty pages. 138 return DumpImageDiffMap(image_diff_pid, boot_map); 139 } 140 141 // Look at /proc/$pid/mem and only diff the things from there 142 bool DumpImageDiffMap(pid_t image_diff_pid, const backtrace_map_t& boot_map) 143 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 144 std::ostream& os = *os_; 145 const size_t pointer_size = InstructionSetPointerSize( 146 Runtime::Current()->GetInstructionSet()); 147 148 std::string file_name = 149 StringPrintf("/proc/%ld/mem", static_cast<long>(image_diff_pid)); // NOLINT [runtime/int] 150 151 size_t boot_map_size = boot_map.end - boot_map.start; 152 153 // Open /proc/$pid/mem as a file 154 auto map_file = std::unique_ptr<File>(OS::OpenFileForReading(file_name.c_str())); 155 if (map_file == nullptr) { 156 os << "Failed to open " << file_name << " for reading"; 157 return false; 158 } 159 160 // Memory-map /proc/$pid/mem subset from the boot map 161 CHECK(boot_map.end >= boot_map.start); 162 163 std::string error_msg; 164 165 // Walk the bytes and diff against our boot image 166 const ImageHeader& boot_image_header = GetBootImageHeader(); 167 168 os << "\nObserving boot image header at address " 169 << reinterpret_cast<const void*>(&boot_image_header) 170 << "\n\n"; 171 172 const uint8_t* image_begin_unaligned = boot_image_header.GetImageBegin(); 173 const uint8_t* image_mirror_end_unaligned = image_begin_unaligned + 174 boot_image_header.GetImageSection(ImageHeader::kSectionObjects).Size(); 175 const uint8_t* image_end_unaligned = image_begin_unaligned + boot_image_header.GetImageSize(); 176 177 // Adjust range to nearest page 178 const uint8_t* image_begin = AlignDown(image_begin_unaligned, kPageSize); 179 const uint8_t* image_end = AlignUp(image_end_unaligned, kPageSize); 180 181 ptrdiff_t page_off_begin = boot_image_header.GetImageBegin() - image_begin; 182 183 if (reinterpret_cast<uintptr_t>(image_begin) > boot_map.start || 184 reinterpret_cast<uintptr_t>(image_end) < boot_map.end) { 185 // Sanity check that we aren't trying to read a completely different boot image 186 os << "Remote boot map is out of range of local boot map: " << 187 "local begin " << reinterpret_cast<const void*>(image_begin) << 188 ", local end " << reinterpret_cast<const void*>(image_end) << 189 ", remote begin " << reinterpret_cast<const void*>(boot_map.start) << 190 ", remote end " << reinterpret_cast<const void*>(boot_map.end); 191 return false; 192 // If we wanted even more validation we could map the ImageHeader from the file 193 } 194 195 std::vector<uint8_t> remote_contents(boot_map_size); 196 if (!map_file->PreadFully(&remote_contents[0], boot_map_size, boot_map.start)) { 197 os << "Could not fully read file " << file_name; 198 return false; 199 } 200 201 std::string page_map_file_name = StringPrintf( 202 "/proc/%ld/pagemap", static_cast<long>(image_diff_pid)); // NOLINT [runtime/int] 203 auto page_map_file = std::unique_ptr<File>(OS::OpenFileForReading(page_map_file_name.c_str())); 204 if (page_map_file == nullptr) { 205 os << "Failed to open " << page_map_file_name << " for reading: " << strerror(errno); 206 return false; 207 } 208 209 // Not truly clean, mmap-ing boot.art again would be more pristine, but close enough 210 const char* clean_page_map_file_name = "/proc/self/pagemap"; 211 auto clean_page_map_file = std::unique_ptr<File>( 212 OS::OpenFileForReading(clean_page_map_file_name)); 213 if (clean_page_map_file == nullptr) { 214 os << "Failed to open " << clean_page_map_file_name << " for reading: " << strerror(errno); 215 return false; 216 } 217 218 auto kpage_flags_file = std::unique_ptr<File>(OS::OpenFileForReading("/proc/kpageflags")); 219 if (kpage_flags_file == nullptr) { 220 os << "Failed to open /proc/kpageflags for reading: " << strerror(errno); 221 return false; 222 } 223 224 auto kpage_count_file = std::unique_ptr<File>(OS::OpenFileForReading("/proc/kpagecount")); 225 if (kpage_count_file == nullptr) { 226 os << "Failed to open /proc/kpagecount for reading:" << strerror(errno); 227 return false; 228 } 229 230 // Set of the remote virtual page indices that are dirty 231 std::set<size_t> dirty_page_set_remote; 232 // Set of the local virtual page indices that are dirty 233 std::set<size_t> dirty_page_set_local; 234 235 size_t different_int32s = 0; 236 size_t different_bytes = 0; 237 size_t different_pages = 0; 238 size_t virtual_page_idx = 0; // Virtual page number (for an absolute memory address) 239 size_t page_idx = 0; // Page index relative to 0 240 size_t previous_page_idx = 0; // Previous page index relative to 0 241 size_t dirty_pages = 0; 242 size_t private_pages = 0; 243 size_t private_dirty_pages = 0; 244 245 // Iterate through one page at a time. Boot map begin/end already implicitly aligned. 246 for (uintptr_t begin = boot_map.start; begin != boot_map.end; begin += kPageSize) { 247 ptrdiff_t offset = begin - boot_map.start; 248 249 // We treat the image header as part of the memory map for now 250 // If we wanted to change this, we could pass base=start+sizeof(ImageHeader) 251 // But it might still be interesting to see if any of the ImageHeader data mutated 252 const uint8_t* local_ptr = reinterpret_cast<const uint8_t*>(&boot_image_header) + offset; 253 uint8_t* remote_ptr = &remote_contents[offset]; 254 255 if (memcmp(local_ptr, remote_ptr, kPageSize) != 0) { 256 different_pages++; 257 258 // Count the number of 32-bit integers that are different. 259 for (size_t i = 0; i < kPageSize / sizeof(uint32_t); ++i) { 260 uint32_t* remote_ptr_int32 = reinterpret_cast<uint32_t*>(remote_ptr); 261 const uint32_t* local_ptr_int32 = reinterpret_cast<const uint32_t*>(local_ptr); 262 263 if (remote_ptr_int32[i] != local_ptr_int32[i]) { 264 different_int32s++; 265 } 266 } 267 } 268 } 269 270 // Iterate through one byte at a time. 271 for (uintptr_t begin = boot_map.start; begin != boot_map.end; ++begin) { 272 previous_page_idx = page_idx; 273 ptrdiff_t offset = begin - boot_map.start; 274 275 // We treat the image header as part of the memory map for now 276 // If we wanted to change this, we could pass base=start+sizeof(ImageHeader) 277 // But it might still be interesting to see if any of the ImageHeader data mutated 278 const uint8_t* local_ptr = reinterpret_cast<const uint8_t*>(&boot_image_header) + offset; 279 uint8_t* remote_ptr = &remote_contents[offset]; 280 281 virtual_page_idx = reinterpret_cast<uintptr_t>(local_ptr) / kPageSize; 282 283 // Calculate the page index, relative to the 0th page where the image begins 284 page_idx = (offset + page_off_begin) / kPageSize; 285 if (*local_ptr != *remote_ptr) { 286 // Track number of bytes that are different 287 different_bytes++; 288 } 289 290 // Independently count the # of dirty pages on the remote side 291 size_t remote_virtual_page_idx = begin / kPageSize; 292 if (previous_page_idx != page_idx) { 293 uint64_t page_count = 0xC0FFEE; 294 // TODO: virtual_page_idx needs to be from the same process 295 int dirtiness = (IsPageDirty(page_map_file.get(), // Image-diff-pid procmap 296 clean_page_map_file.get(), // Self procmap 297 kpage_flags_file.get(), 298 kpage_count_file.get(), 299 remote_virtual_page_idx, // potentially "dirty" page 300 virtual_page_idx, // true "clean" page 301 &page_count, 302 &error_msg)); 303 if (dirtiness < 0) { 304 os << error_msg; 305 return false; 306 } else if (dirtiness > 0) { 307 dirty_pages++; 308 dirty_page_set_remote.insert(dirty_page_set_remote.end(), remote_virtual_page_idx); 309 dirty_page_set_local.insert(dirty_page_set_local.end(), virtual_page_idx); 310 } 311 312 bool is_dirty = dirtiness > 0; 313 bool is_private = page_count == 1; 314 315 if (page_count == 1) { 316 private_pages++; 317 } 318 319 if (is_dirty && is_private) { 320 private_dirty_pages++; 321 } 322 } 323 } 324 325 // Walk each object in the remote image space and compare it against ours 326 size_t different_objects = 0; 327 std::map<mirror::Class*, int /*count*/> dirty_object_class_map; 328 // Track only the byte-per-byte dirtiness (in bytes) 329 std::map<mirror::Class*, int /*byte_count*/> dirty_object_byte_count; 330 // Track the object-by-object dirtiness (in bytes) 331 std::map<mirror::Class*, int /*byte_count*/> dirty_object_size_in_bytes; 332 std::map<mirror::Class*, int /*count*/> clean_object_class_map; 333 334 std::map<mirror::Class*, std::string> class_to_descriptor_map; 335 336 std::map<off_t /* field offset */, int /* count */> art_method_field_dirty_count; 337 std::vector<ArtMethod*> art_method_dirty_objects; 338 339 std::map<off_t /* field offset */, int /* count */> class_field_dirty_count; 340 std::vector<mirror::Class*> class_dirty_objects; 341 342 // List of local objects that are clean, but located on dirty pages. 343 std::vector<mirror::Object*> false_dirty_objects; 344 std::map<mirror::Class*, int /*byte_count*/> false_dirty_byte_count; 345 std::map<mirror::Class*, int /*object_count*/> false_dirty_object_count; 346 std::map<mirror::Class*, std::vector<mirror::Object*>> false_dirty_objects_map; 347 size_t false_dirty_object_bytes = 0; 348 349 // Remote pointers to dirty objects 350 std::map<mirror::Class*, std::vector<mirror::Object*>> dirty_objects_by_class; 351 // Look up remote classes by their descriptor 352 std::map<std::string, mirror::Class*> remote_class_map; 353 // Look up local classes by their descriptor 354 std::map<std::string, mirror::Class*> local_class_map; 355 356 size_t dirty_object_bytes = 0; 357 { 358 const uint8_t* begin_image_ptr = image_begin_unaligned; 359 const uint8_t* end_image_ptr = image_mirror_end_unaligned; 360 361 const uint8_t* current = begin_image_ptr + RoundUp(sizeof(ImageHeader), kObjectAlignment); 362 while (reinterpret_cast<const uintptr_t>(current) 363 < reinterpret_cast<const uintptr_t>(end_image_ptr)) { 364 CHECK_ALIGNED(current, kObjectAlignment); 365 mirror::Object* obj = reinterpret_cast<mirror::Object*>(const_cast<uint8_t*>(current)); 366 367 // Sanity check that we are reading a real object 368 CHECK(obj->GetClass() != nullptr) << "Image object at address " << obj << " has null class"; 369 if (kUseBakerOrBrooksReadBarrier) { 370 obj->AssertReadBarrierPointer(); 371 } 372 373 // Iterate every page this object belongs to 374 bool on_dirty_page = false; 375 size_t page_off = 0; 376 size_t current_page_idx; 377 uintptr_t object_address; 378 do { 379 object_address = reinterpret_cast<uintptr_t>(current); 380 current_page_idx = object_address / kPageSize + page_off; 381 382 if (dirty_page_set_local.find(current_page_idx) != dirty_page_set_local.end()) { 383 // This object is on a dirty page 384 on_dirty_page = true; 385 } 386 387 page_off++; 388 } while ((current_page_idx * kPageSize) < 389 RoundUp(object_address + obj->SizeOf(), kObjectAlignment)); 390 391 mirror::Class* klass = obj->GetClass(); 392 393 bool different_object = false; 394 395 // Check against the other object and see if they are different 396 ptrdiff_t offset = current - begin_image_ptr; 397 const uint8_t* current_remote = &remote_contents[offset]; 398 mirror::Object* remote_obj = reinterpret_cast<mirror::Object*>( 399 const_cast<uint8_t*>(current_remote)); 400 if (memcmp(current, current_remote, obj->SizeOf()) != 0) { 401 different_objects++; 402 dirty_object_bytes += obj->SizeOf(); 403 404 ++dirty_object_class_map[klass]; 405 406 // Go byte-by-byte and figure out what exactly got dirtied 407 size_t dirty_byte_count_per_object = 0; 408 for (size_t i = 0; i < obj->SizeOf(); ++i) { 409 if (current[i] != current_remote[i]) { 410 dirty_byte_count_per_object++; 411 } 412 } 413 dirty_object_byte_count[klass] += dirty_byte_count_per_object; 414 dirty_object_size_in_bytes[klass] += obj->SizeOf(); 415 416 different_object = true; 417 418 dirty_objects_by_class[klass].push_back(remote_obj); 419 } else { 420 ++clean_object_class_map[klass]; 421 } 422 423 std::string descriptor = GetClassDescriptor(klass); 424 if (different_object) { 425 if (strcmp(descriptor.c_str(), "Ljava/lang/Class;") == 0) { 426 // this is a "Class" 427 mirror::Class* obj_as_class = reinterpret_cast<mirror::Class*>(remote_obj); 428 429 // print the fields that are dirty 430 for (size_t i = 0; i < obj->SizeOf(); ++i) { 431 if (current[i] != current_remote[i]) { 432 class_field_dirty_count[i]++; 433 } 434 } 435 436 class_dirty_objects.push_back(obj_as_class); 437 } else if (strcmp(descriptor.c_str(), "Ljava/lang/reflect/ArtMethod;") == 0) { 438 // this is an ArtMethod 439 ArtMethod* art_method = reinterpret_cast<ArtMethod*>(remote_obj); 440 441 // print the fields that are dirty 442 for (size_t i = 0; i < obj->SizeOf(); ++i) { 443 if (current[i] != current_remote[i]) { 444 art_method_field_dirty_count[i]++; 445 } 446 } 447 448 art_method_dirty_objects.push_back(art_method); 449 } 450 } else if (on_dirty_page) { 451 // This object was either never mutated or got mutated back to the same value. 452 // TODO: Do I want to distinguish a "different" vs a "dirty" page here? 453 false_dirty_objects.push_back(obj); 454 false_dirty_objects_map[klass].push_back(obj); 455 false_dirty_object_bytes += obj->SizeOf(); 456 false_dirty_byte_count[obj->GetClass()] += obj->SizeOf(); 457 false_dirty_object_count[obj->GetClass()] += 1; 458 } 459 460 if (strcmp(descriptor.c_str(), "Ljava/lang/Class;") == 0) { 461 local_class_map[descriptor] = reinterpret_cast<mirror::Class*>(obj); 462 remote_class_map[descriptor] = reinterpret_cast<mirror::Class*>(remote_obj); 463 } 464 465 // Unconditionally store the class descriptor in case we need it later 466 class_to_descriptor_map[klass] = descriptor; 467 current += RoundUp(obj->SizeOf(), kObjectAlignment); 468 } 469 } 470 471 // Looking at only dirty pages, figure out how many of those bytes belong to dirty objects. 472 float true_dirtied_percent = dirty_object_bytes * 1.0f / (dirty_pages * kPageSize); 473 size_t false_dirty_pages = dirty_pages - different_pages; 474 475 os << "Mapping at [" << reinterpret_cast<void*>(boot_map.start) << ", " 476 << reinterpret_cast<void*>(boot_map.end) << ") had: \n " 477 << different_bytes << " differing bytes, \n " 478 << different_int32s << " differing int32s, \n " 479 << different_objects << " different objects, \n " 480 << dirty_object_bytes << " different object [bytes], \n " 481 << false_dirty_objects.size() << " false dirty objects,\n " 482 << false_dirty_object_bytes << " false dirty object [bytes], \n " 483 << true_dirtied_percent << " different objects-vs-total in a dirty page;\n " 484 << different_pages << " different pages; \n " 485 << dirty_pages << " pages are dirty; \n " 486 << false_dirty_pages << " pages are false dirty; \n " 487 << private_pages << " pages are private; \n " 488 << private_dirty_pages << " pages are Private_Dirty\n " 489 << ""; 490 491 // vector of pairs (int count, Class*) 492 auto dirty_object_class_values = SortByValueDesc(dirty_object_class_map); 493 auto clean_object_class_values = SortByValueDesc(clean_object_class_map); 494 495 os << "\n" << " Dirty object count by class:\n"; 496 for (const auto& vk_pair : dirty_object_class_values) { 497 int dirty_object_count = vk_pair.first; 498 mirror::Class* klass = vk_pair.second; 499 int object_sizes = dirty_object_size_in_bytes[klass]; 500 float avg_dirty_bytes_per_class = dirty_object_byte_count[klass] * 1.0f / object_sizes; 501 float avg_object_size = object_sizes * 1.0f / dirty_object_count; 502 const std::string& descriptor = class_to_descriptor_map[klass]; 503 os << " " << PrettyClass(klass) << " (" 504 << "objects: " << dirty_object_count << ", " 505 << "avg dirty bytes: " << avg_dirty_bytes_per_class << ", " 506 << "avg object size: " << avg_object_size << ", " 507 << "class descriptor: '" << descriptor << "'" 508 << ")\n"; 509 510 constexpr size_t kMaxAddressPrint = 5; 511 if (strcmp(descriptor.c_str(), "Ljava/lang/reflect/ArtMethod;") == 0) { 512 os << " sample object addresses: "; 513 for (size_t i = 0; i < art_method_dirty_objects.size() && i < kMaxAddressPrint; ++i) { 514 auto art_method = art_method_dirty_objects[i]; 515 516 os << reinterpret_cast<void*>(art_method) << ", "; 517 } 518 os << "\n"; 519 520 os << " dirty byte +offset:count list = "; 521 auto art_method_field_dirty_count_sorted = SortByValueDesc(art_method_field_dirty_count); 522 for (auto pair : art_method_field_dirty_count_sorted) { 523 off_t offset = pair.second; 524 int count = pair.first; 525 526 os << "+" << offset << ":" << count << ", "; 527 } 528 529 os << "\n"; 530 531 os << " field contents:\n"; 532 const auto& dirty_objects_list = dirty_objects_by_class[klass]; 533 for (mirror::Object* obj : dirty_objects_list) { 534 // remote method 535 auto art_method = reinterpret_cast<ArtMethod*>(obj); 536 537 // remote class 538 mirror::Class* remote_declaring_class = 539 FixUpRemotePointer(art_method->GetDeclaringClass(), remote_contents, boot_map); 540 541 // local class 542 mirror::Class* declaring_class = 543 RemoteContentsPointerToLocal(remote_declaring_class, 544 remote_contents, 545 boot_image_header); 546 547 os << " " << reinterpret_cast<void*>(obj) << " "; 548 os << " entryPointFromJni: " 549 << reinterpret_cast<const void*>( 550 art_method->GetEntryPointFromJniPtrSize(pointer_size)) << ", "; 551 os << " entryPointFromInterpreter: " 552 << reinterpret_cast<const void*>( 553 art_method->GetEntryPointFromInterpreterPtrSize(pointer_size)) 554 << ", "; 555 os << " entryPointFromQuickCompiledCode: " 556 << reinterpret_cast<const void*>( 557 art_method->GetEntryPointFromQuickCompiledCodePtrSize(pointer_size)) 558 << ", "; 559 os << " isNative? " << (art_method->IsNative() ? "yes" : "no") << ", "; 560 os << " class_status (local): " << declaring_class->GetStatus(); 561 os << " class_status (remote): " << remote_declaring_class->GetStatus(); 562 os << "\n"; 563 } 564 } 565 if (strcmp(descriptor.c_str(), "Ljava/lang/Class;") == 0) { 566 os << " sample object addresses: "; 567 for (size_t i = 0; i < class_dirty_objects.size() && i < kMaxAddressPrint; ++i) { 568 auto class_ptr = class_dirty_objects[i]; 569 570 os << reinterpret_cast<void*>(class_ptr) << ", "; 571 } 572 os << "\n"; 573 574 os << " dirty byte +offset:count list = "; 575 auto class_field_dirty_count_sorted = SortByValueDesc(class_field_dirty_count); 576 for (auto pair : class_field_dirty_count_sorted) { 577 off_t offset = pair.second; 578 int count = pair.first; 579 580 os << "+" << offset << ":" << count << ", "; 581 } 582 os << "\n"; 583 584 os << " field contents:\n"; 585 const auto& dirty_objects_list = dirty_objects_by_class[klass]; 586 for (mirror::Object* obj : dirty_objects_list) { 587 // remote class object 588 auto remote_klass = reinterpret_cast<mirror::Class*>(obj); 589 590 // local class object 591 auto local_klass = RemoteContentsPointerToLocal(remote_klass, 592 remote_contents, 593 boot_image_header); 594 595 os << " " << reinterpret_cast<void*>(obj) << " "; 596 os << " class_status (remote): " << remote_klass->GetStatus() << ", "; 597 os << " class_status (local): " << local_klass->GetStatus(); 598 os << "\n"; 599 } 600 } 601 } 602 603 auto false_dirty_object_class_values = SortByValueDesc(false_dirty_object_count); 604 605 os << "\n" << " False-dirty object count by class:\n"; 606 for (const auto& vk_pair : false_dirty_object_class_values) { 607 int object_count = vk_pair.first; 608 mirror::Class* klass = vk_pair.second; 609 int object_sizes = false_dirty_byte_count[klass]; 610 float avg_object_size = object_sizes * 1.0f / object_count; 611 const std::string& descriptor = class_to_descriptor_map[klass]; 612 os << " " << PrettyClass(klass) << " (" 613 << "objects: " << object_count << ", " 614 << "avg object size: " << avg_object_size << ", " 615 << "total bytes: " << object_sizes << ", " 616 << "class descriptor: '" << descriptor << "'" 617 << ")\n"; 618 619 if (strcmp(descriptor.c_str(), "Ljava/lang/reflect/ArtMethod;") == 0) { 620 auto& art_method_false_dirty_objects = false_dirty_objects_map[klass]; 621 622 os << " field contents:\n"; 623 for (mirror::Object* obj : art_method_false_dirty_objects) { 624 // local method 625 auto art_method = reinterpret_cast<ArtMethod*>(obj); 626 627 // local class 628 mirror::Class* declaring_class = art_method->GetDeclaringClass(); 629 630 os << " " << reinterpret_cast<void*>(obj) << " "; 631 os << " entryPointFromJni: " 632 << reinterpret_cast<const void*>( 633 art_method->GetEntryPointFromJniPtrSize(pointer_size)) << ", "; 634 os << " entryPointFromInterpreter: " 635 << reinterpret_cast<const void*>( 636 art_method->GetEntryPointFromInterpreterPtrSize(pointer_size)) 637 << ", "; 638 os << " entryPointFromQuickCompiledCode: " 639 << reinterpret_cast<const void*>( 640 art_method->GetEntryPointFromQuickCompiledCodePtrSize(pointer_size)) 641 << ", "; 642 os << " isNative? " << (art_method->IsNative() ? "yes" : "no") << ", "; 643 os << " class_status (local): " << declaring_class->GetStatus(); 644 os << "\n"; 645 } 646 } 647 } 648 649 os << "\n" << " Clean object count by class:\n"; 650 for (const auto& vk_pair : clean_object_class_values) { 651 os << " " << PrettyClass(vk_pair.second) << " (" << vk_pair.first << ")\n"; 652 } 653 654 return true; 655 } 656 657 // Fixup a remote pointer that we read from a foreign boot.art to point to our own memory. 658 // Returned pointer will point to inside of remote_contents. 659 template <typename T> 660 static T* FixUpRemotePointer(T* remote_ptr, 661 std::vector<uint8_t>& remote_contents, 662 const backtrace_map_t& boot_map) { 663 if (remote_ptr == nullptr) { 664 return nullptr; 665 } 666 667 uintptr_t remote = reinterpret_cast<uintptr_t>(remote_ptr); 668 669 CHECK_LE(boot_map.start, remote); 670 CHECK_GT(boot_map.end, remote); 671 672 off_t boot_offset = remote - boot_map.start; 673 674 return reinterpret_cast<T*>(&remote_contents[boot_offset]); 675 } 676 677 template <typename T> 678 static T* RemoteContentsPointerToLocal(T* remote_ptr, 679 std::vector<uint8_t>& remote_contents, 680 const ImageHeader& image_header) { 681 if (remote_ptr == nullptr) { 682 return nullptr; 683 } 684 685 uint8_t* remote = reinterpret_cast<uint8_t*>(remote_ptr); 686 ptrdiff_t boot_offset = remote - &remote_contents[0]; 687 688 const uint8_t* local_ptr = reinterpret_cast<const uint8_t*>(&image_header) + boot_offset; 689 690 return reinterpret_cast<T*>(const_cast<uint8_t*>(local_ptr)); 691 } 692 693 static std::string GetClassDescriptor(mirror::Class* klass) 694 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 695 CHECK(klass != nullptr); 696 697 std::string descriptor; 698 const char* descriptor_str = klass->GetDescriptor(&descriptor); 699 700 return std::string(descriptor_str); 701 } 702 703 template <typename K, typename V> 704 static std::vector<std::pair<V, K>> SortByValueDesc(const std::map<K, V> map) { 705 // Store value->key so that we can use the default sort from pair which 706 // sorts by value first and then key 707 std::vector<std::pair<V, K>> value_key_vector; 708 709 for (const auto& kv_pair : map) { 710 value_key_vector.push_back(std::make_pair(kv_pair.second, kv_pair.first)); 711 } 712 713 // Sort in reverse (descending order) 714 std::sort(value_key_vector.rbegin(), value_key_vector.rend()); 715 return value_key_vector; 716 } 717 718 static bool GetPageFrameNumber(File* page_map_file, 719 size_t virtual_page_index, 720 uint64_t* page_frame_number, 721 std::string* error_msg) { 722 CHECK(page_map_file != nullptr); 723 CHECK(page_frame_number != nullptr); 724 CHECK(error_msg != nullptr); 725 726 constexpr size_t kPageMapEntrySize = sizeof(uint64_t); 727 constexpr uint64_t kPageFrameNumberMask = (1ULL << 55) - 1; // bits 0-54 [in /proc/$pid/pagemap] 728 constexpr uint64_t kPageSoftDirtyMask = (1ULL << 55); // bit 55 [in /proc/$pid/pagemap] 729 730 uint64_t page_map_entry = 0; 731 732 // Read 64-bit entry from /proc/$pid/pagemap to get the physical page frame number 733 if (!page_map_file->PreadFully(&page_map_entry, kPageMapEntrySize, 734 virtual_page_index * kPageMapEntrySize)) { 735 *error_msg = StringPrintf("Failed to read the virtual page index entry from %s", 736 page_map_file->GetPath().c_str()); 737 return false; 738 } 739 740 // TODO: seems useless, remove this. 741 bool soft_dirty = (page_map_entry & kPageSoftDirtyMask) != 0; 742 if ((false)) { 743 LOG(VERBOSE) << soft_dirty; // Suppress unused warning 744 UNREACHABLE(); 745 } 746 747 *page_frame_number = page_map_entry & kPageFrameNumberMask; 748 749 return true; 750 } 751 752 static int IsPageDirty(File* page_map_file, 753 File* clean_page_map_file, 754 File* kpage_flags_file, 755 File* kpage_count_file, 756 size_t virtual_page_idx, 757 size_t clean_virtual_page_idx, 758 // Out parameters: 759 uint64_t* page_count, std::string* error_msg) { 760 CHECK(page_map_file != nullptr); 761 CHECK(clean_page_map_file != nullptr); 762 CHECK_NE(page_map_file, clean_page_map_file); 763 CHECK(kpage_flags_file != nullptr); 764 CHECK(kpage_count_file != nullptr); 765 CHECK(page_count != nullptr); 766 CHECK(error_msg != nullptr); 767 768 // Constants are from https://www.kernel.org/doc/Documentation/vm/pagemap.txt 769 770 constexpr size_t kPageFlagsEntrySize = sizeof(uint64_t); 771 constexpr size_t kPageCountEntrySize = sizeof(uint64_t); 772 constexpr uint64_t kPageFlagsDirtyMask = (1ULL << 4); // in /proc/kpageflags 773 constexpr uint64_t kPageFlagsNoPageMask = (1ULL << 20); // in /proc/kpageflags 774 constexpr uint64_t kPageFlagsMmapMask = (1ULL << 11); // in /proc/kpageflags 775 776 uint64_t page_frame_number = 0; 777 if (!GetPageFrameNumber(page_map_file, virtual_page_idx, &page_frame_number, error_msg)) { 778 return -1; 779 } 780 781 uint64_t page_frame_number_clean = 0; 782 if (!GetPageFrameNumber(clean_page_map_file, clean_virtual_page_idx, &page_frame_number_clean, 783 error_msg)) { 784 return -1; 785 } 786 787 // Read 64-bit entry from /proc/kpageflags to get the dirty bit for a page 788 uint64_t kpage_flags_entry = 0; 789 if (!kpage_flags_file->PreadFully(&kpage_flags_entry, 790 kPageFlagsEntrySize, 791 page_frame_number * kPageFlagsEntrySize)) { 792 *error_msg = StringPrintf("Failed to read the page flags from %s", 793 kpage_flags_file->GetPath().c_str()); 794 return -1; 795 } 796 797 // Read 64-bit entyry from /proc/kpagecount to get mapping counts for a page 798 if (!kpage_count_file->PreadFully(page_count /*out*/, 799 kPageCountEntrySize, 800 page_frame_number * kPageCountEntrySize)) { 801 *error_msg = StringPrintf("Failed to read the page count from %s", 802 kpage_count_file->GetPath().c_str()); 803 return -1; 804 } 805 806 // There must be a page frame at the requested address. 807 CHECK_EQ(kpage_flags_entry & kPageFlagsNoPageMask, 0u); 808 // The page frame must be memory mapped 809 CHECK_NE(kpage_flags_entry & kPageFlagsMmapMask, 0u); 810 811 // Page is dirty, i.e. has diverged from file, if the 4th bit is set to 1 812 bool flags_dirty = (kpage_flags_entry & kPageFlagsDirtyMask) != 0; 813 814 // page_frame_number_clean must come from the *same* process 815 // but a *different* mmap than page_frame_number 816 if (flags_dirty) { 817 CHECK_NE(page_frame_number, page_frame_number_clean); 818 } 819 820 return page_frame_number != page_frame_number_clean; 821 } 822 823 static const ImageHeader& GetBootImageHeader() { 824 gc::Heap* heap = Runtime::Current()->GetHeap(); 825 gc::space::ImageSpace* image_space = heap->GetImageSpace(); 826 CHECK(image_space != nullptr); 827 const ImageHeader& image_header = image_space->GetImageHeader(); 828 return image_header; 829 } 830 831 private: 832 // Return the image location, stripped of any directories, e.g. "boot.art" or "core.art" 833 std::string GetImageLocationBaseName() const { 834 return BaseName(std::string(image_location_)); 835 } 836 837 std::ostream* os_; 838 const ImageHeader& image_header_; 839 const char* image_location_; 840 pid_t image_diff_pid_; // Dump image diff against boot.art if pid is non-negative 841 842 DISALLOW_COPY_AND_ASSIGN(ImgDiagDumper); 843 }; 844 845 static int DumpImage(Runtime* runtime, const char* image_location, 846 std::ostream* os, pid_t image_diff_pid) { 847 ScopedObjectAccess soa(Thread::Current()); 848 gc::Heap* heap = runtime->GetHeap(); 849 gc::space::ImageSpace* image_space = heap->GetImageSpace(); 850 CHECK(image_space != nullptr); 851 const ImageHeader& image_header = image_space->GetImageHeader(); 852 if (!image_header.IsValid()) { 853 fprintf(stderr, "Invalid image header %s\n", image_location); 854 return EXIT_FAILURE; 855 } 856 857 ImgDiagDumper img_diag_dumper(os, image_header, image_location, image_diff_pid); 858 859 bool success = img_diag_dumper.Dump(); 860 return (success) ? EXIT_SUCCESS : EXIT_FAILURE; 861 } 862 863 struct ImgDiagArgs : public CmdlineArgs { 864 protected: 865 using Base = CmdlineArgs; 866 867 virtual ParseStatus ParseCustom(const StringPiece& option, 868 std::string* error_msg) OVERRIDE { 869 { 870 ParseStatus base_parse = Base::ParseCustom(option, error_msg); 871 if (base_parse != kParseUnknownArgument) { 872 return base_parse; 873 } 874 } 875 876 if (option.starts_with("--image-diff-pid=")) { 877 const char* image_diff_pid = option.substr(strlen("--image-diff-pid=")).data(); 878 879 if (!ParseInt(image_diff_pid, &image_diff_pid_)) { 880 *error_msg = "Image diff pid out of range"; 881 return kParseError; 882 } 883 } else { 884 return kParseUnknownArgument; 885 } 886 887 return kParseOk; 888 } 889 890 virtual ParseStatus ParseChecks(std::string* error_msg) OVERRIDE { 891 // Perform the parent checks. 892 ParseStatus parent_checks = Base::ParseChecks(error_msg); 893 if (parent_checks != kParseOk) { 894 return parent_checks; 895 } 896 897 // Perform our own checks. 898 899 if (kill(image_diff_pid_, 900 /*sig*/0) != 0) { // No signal is sent, perform error-checking only. 901 // Check if the pid exists before proceeding. 902 if (errno == ESRCH) { 903 *error_msg = "Process specified does not exist"; 904 } else { 905 *error_msg = StringPrintf("Failed to check process status: %s", strerror(errno)); 906 } 907 return kParseError; 908 } else if (instruction_set_ != kRuntimeISA) { 909 // Don't allow different ISAs since the images are ISA-specific. 910 // Right now the code assumes both the runtime ISA and the remote ISA are identical. 911 *error_msg = "Must use the default runtime ISA; changing ISA is not supported."; 912 return kParseError; 913 } 914 915 return kParseOk; 916 } 917 918 virtual std::string GetUsage() const { 919 std::string usage; 920 921 usage += 922 "Usage: imgdiag [options] ...\n" 923 " Example: imgdiag --image-diff-pid=$(pidof dex2oat)\n" 924 " Example: adb shell imgdiag --image-diff-pid=$(pid zygote)\n" 925 "\n"; 926 927 usage += Base::GetUsage(); 928 929 usage += // Optional. 930 " --image-diff-pid=<pid>: provide the PID of a process whose boot.art you want to diff.\n" 931 " Example: --image-diff-pid=$(pid zygote)\n" 932 "\n"; 933 934 return usage; 935 } 936 937 public: 938 pid_t image_diff_pid_ = -1; 939 }; 940 941 struct ImgDiagMain : public CmdlineMain<ImgDiagArgs> { 942 virtual bool ExecuteWithRuntime(Runtime* runtime) { 943 CHECK(args_ != nullptr); 944 945 return DumpImage(runtime, 946 args_->boot_image_location_, 947 args_->os_, 948 args_->image_diff_pid_) == EXIT_SUCCESS; 949 } 950 }; 951 952 } // namespace art 953 954 int main(int argc, char** argv) { 955 art::ImgDiagMain main; 956 return main.Main(argc, argv); 957 } 958
